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Organic Letters Feb 2020Amines such as 1,2,3,4-tetrahydroisoquinoline undergo redox-neutral annulations with -cyanomethylbenzaldehydes. These amine α-C-H bond functionalization reactions are...
Amines such as 1,2,3,4-tetrahydroisoquinoline undergo redox-neutral annulations with -cyanomethylbenzaldehydes. These amine α-C-H bond functionalization reactions are promoted by acetic acid. The resulting β-aminonitriles can be converted to the corresponding β-aminoalcohols in diastereoselective fashion.
Topics: Acetic Acid; Amino Alcohols; Benzaldehydes; Molecular Structure; Oxidation-Reduction; Stereoisomerism; Tetrahydroisoquinolines
PubMed: 31984752
DOI: 10.1021/acs.orglett.9b04506 -
ChemSusChem Aug 2022The synthesis of acetic acid by formal isomerization of methyl formate (MF) was investigated using molecular catalysts. The base-catalyzed decarbonylation of MF,...
The synthesis of acetic acid by formal isomerization of methyl formate (MF) was investigated using molecular catalysts. The base-catalyzed decarbonylation of MF, yielding CO and methanol in situ, was integrated with their palladium-catalyzed recombination for the synthesis of acetic acid and methyl acetate in a one pot reaction. The complex [Pd(Cl) (dppe)] [dppe=1,2-bis(diphenylphosphino)-ethane] in combination with NaI as iodide source and NaOMe as base were identified as promising molecular components to enable the overall conversion. Sequential application of the statistical methods design of experiments and simplex optimization was used in combination with thermodynamic analysis of the competing reaction pathways for experimental planning and data analysis. Starting from a proof-of-principle with a turnover number (TON) of 11, the catalytic system could thus be optimized to allow quantitative conversion of MF with a TON of 43000, whereby a yield of 83 % of acetate groups and a yield of 74 % for free acetic acid was obtained.
Topics: Acetic Acid; Catalysis; Formic Acid Esters; Isomerism; Molecular Structure; Palladium
PubMed: 35691934
DOI: 10.1002/cssc.202201006 -
Water Research Mar 2021Trichloroacetic acid (TCAA) is a common disinfection byproduct (DBP) produced during chlorine disinfection. With the outbreak of the Coronavirus Disease 2019 (COVID-19)...
Trichloroacetic acid (TCAA) is a common disinfection byproduct (DBP) produced during chlorine disinfection. With the outbreak of the Coronavirus Disease 2019 (COVID-19) pandemic, the use of chlorine disinfection has increased, raising the already substantial risks of DBP exposure. While a number of methods are able to remove TCAA, their application for continuous treatment is limited due to their complexity and expensive or hazardous inputs. We investigated a novel system that employs palladium (Pd) nanoparticles (PdNPs) for catalytic reductive dechlorination of TCAA. H was delivered directly to PdNPs in situ coated on the surface of bubble-free hollow-fiber gas-transfer membranes. The H-based membrane Pd film reactor (H-MPfR) achieved a high catalyst-specific TCAA reduction rate, 32 L/g-Pd/min, a value similar to the rate of using homogeneously suspended PdNP, but orders of magnitude higher than with other immobilized PdNP systems. In batch tests, over 99% removal of 1 mM TCAA was achieved in 180 min with strong product selectivity (≥ 93%) to acetic acid. During 50 days of continuous operation, over 99% of 1 mg/L influent TCAA was removed, again with acetic acid as the major product (≥ 94%). We identified the reaction pathways and their kinetics for TCAA reductive dechlorination with PdNPs using direct delivery of H. Sustained continuous TCAA removal, high selectivity to acetic acid, and minimal loss of PdNPs support that the H-MPfR is a promising catalytic reactor to remove chlorinated DBPs in practice.
Topics: Acetic Acid; COVID-19; Catalysis; Humans; Metal Nanoparticles; Palladium; SARS-CoV-2; Trichloroacetic Acid
PubMed: 33503571
DOI: 10.1016/j.watres.2021.116841 -
Current Microbiology Mar 2021Photodynamic inactivation (PDI) is an attractive treatment modality for multidrug-resistant bacterial infections. The effectiveness of photosensitization by anionic...
Photodynamic inactivation (PDI) is an attractive treatment modality for multidrug-resistant bacterial infections. The effectiveness of photosensitization by anionic photosensitizers such as erythrosine B can be further enhanced by the addition of biological or chemical molecules. This study aimed to investigate of the enhancement effect of acetic acid and chitosan on erythrosine-mediated PDI of Acinetobacter baumannii in planktonic and biofilm forms. The planktonic cell growth of three A. baumannii strains was subjected to PDI by using erythrosine B (50 µM) in 0.01% acetic acid and green laser light (530 nm) at fluence of 40 J/cm. The phototoxic effect of erythrosine B (100 µM) in combination with chitosan (12.5 mg/ml) (in a solution of acetic acid) at fluence of 80 J/cm2 on biofilms was also evaluated. Finally, the cytotoxicity and phototoxicity of the mentioned mixture were assessed on human fibroblasts. Planktonic cells of all three studied A. baumannii strains were almost eradicated by erythrosine B-mediated PDI in the presence of acetic acid. Also, PDI combined with chitosan resulted in a marked decrease in the number of viable biofilm cells (> 3 log CFU). At the same experimental conditions, only 15% of the fibroblasts were photoinactivated. The results showed that PDI by using erythrosine B in acetic acid is very effective against A. baumannii planktonic cells and could eliminate them significantly. Also, chitosan enhanced the anti-biofilm efficacy of erythrosine B-mediated PDI against A. baumannii, suggesting that combination therapy may be useful in targeting biofilms.
Topics: Acetic Acid; Acinetobacter baumannii; Biofilms; Chitosan; Erythrosine; Humans; Photosensitizing Agents; Plankton
PubMed: 33512576
DOI: 10.1007/s00284-021-02350-x -
Journal of Dairy Science Mar 2018Effects of continuous isomolar infusions of acetic acid (AcA) or sodium acetate (NAc) infused into the rumen (RU) or into the abomasum (AB) on feeding behavior, dry...
Effects of continuous isomolar infusions of acetic acid (AcA) or sodium acetate (NAc) infused into the rumen (RU) or into the abomasum (AB) on feeding behavior, dry matter intake (DMI), and metabolic response of cows in the early postpartum period were evaluated. Six rumen-cannulated multiparous Holstein cows (11.8 ± 3.9 d in milk; mean ± SD) were utilized in a 6 × 6 Latin square design experiment balanced for carryover effects with a 2 × 3 factorial arrangement of treatments. Treatments were AcA and NAc, with sodium chloride (CON) as a control, infused at a rate of ˜0.75 mol/h (0.5 L/h) into the RU or AB for the first 8 h following feeding, with a rest day between infusion days. Treatment sequences were assigned randomly to cows. Feeding behavior was recorded by a computerized data acquisition system and blood was sampled at 0, 4, and 8 h relative to the start of infusion. We hypothesized that AcA is more hypophagic than NAc, and that infusion into the AB is more hypophagic than infusion into the RU. Dry matter intakes (DMI) for the CON treatments were similar at 6.2 kg/8 h for RU and 6.1 kg/8 h for AB, and the AcA and NAc treatments interacted with site of infusion to affect DMI. The NAc-RU treatment did not reduce DMI (7.0 kg/8 h), whereas AcA-RU (2.6 kg/8 h), AcA-AB (3.7 kg/8 h), and NAc-AB (4.0 kg/8 h) decreased DMI compared with CON. Following infusions of AcA compared with NAc, there was a residual effect on DMI for the remainder of the day, but treatments did not affect DMI during the rest day. Treatments increased plasma acetate and β-hydroxybutyrate concentrations over time (interaction) and decreased plasma insulin concentration compared with CON. Plasma glucose concentration decreased over time after AcA-AB infusion compared with other treatments and CON. Plasma nonesterified fatty acid concentration increased over time for AcA compared with NAc and CON, suggesting an increase in lipolysis to compensate the decrease in DMI. In contrast to the other treatments, NAc-RU did not decrease DMI compared with control but we cannot determine the reason for this from the data available from the current study.
Topics: Abomasum; Acetic Acid; Animals; Cattle; Energy Metabolism; Feeding Behavior; Female; Postpartum Period; Random Allocation; Rumen; Sodium Acetate
PubMed: 29398027
DOI: 10.3168/jds.2017-13609 -
Biocontrol Science 20135a-h, a series of (5-substituted-2-methyl-1,3-thiazole-4-yl) acetic acids as heterocyclic acetic acid derivatives, was designed and synthesized from ethyl acetoacetate....
5a-h, a series of (5-substituted-2-methyl-1,3-thiazole-4-yl) acetic acids as heterocyclic acetic acid derivatives, was designed and synthesized from ethyl acetoacetate. The synthesized compounds were screened for their antimicrobial activities against bacterial and fungal strains, and their characteristics were investigated by assays under various temperature and pH conditions. Cytotoxicity was evaluated with the use of sheep erythrocytes and human neonate dermal fibroblasts. Similarly, agents such as lauric acid 6 and parabens 7a-b, which are used as preservative agents for commercial cosmetics and detergents, were assayed for comparison. Although the structure of 5a is simple, comprising a thiazole attached with an octyl group and acetic acid moiety, the compound showed stronger and broader antibacterial and antifungal activities among the 5 series against the tested microbes other than gram-negative bacteria. Interestingly, 5a overcame the weak antifungal activity of parabens 7a-b. Also, the cytotoxicity of 5a was less than that of parabens 7a-b, especially to human dermal fibroblasts. These results suggest that thiazolyl-acetic acid 5a is a potentially effective biocide, and that it could be used as a preservative agent in commercially sold cosmetics and detergents, facilitated by the hydrophilic and charge properties of its carboxylic acid moiety.
Topics: Acetic Acid; Anti-Infective Agents; Bacteria; Cell Line; Cell Survival; Drug Design; Fungi; Humans; Microbial Sensitivity Tests; Molecular Structure; Thiazoles
PubMed: 23796637
DOI: 10.4265/bio.18.59 -
Journal of the American Society of... May 2017Patients enrolled in the African American Study of Kidney Disease and Hypertension (AASK) Cohort Study who exhibited overt proteinuria have been reported to show high...
Patients enrolled in the African American Study of Kidney Disease and Hypertension (AASK) Cohort Study who exhibited overt proteinuria have been reported to show high nonalbumin proteinuria (NAP), which is characteristic of a tubulopathy. To determine whether African American Study of Kidney Disease and Hypertension nephropathy (AASK-N) is a tubulopathy, we obtained urine samples of 37 patients with AASK-N, with 24-hour protein-to-creatinine ratios (milligrams per milligram) ranging from 0.2 to 1.0, from the National Institute of Diabetes and Digestive Kidney Diseases repository and tested for seven markers of tubular proteinuria. By protocol, each sample had been collected in acetic acid (0.5%; mean final concentration). Compared with samples from patients with lupus nephritis or healthy black controls, AASK-N samples had lower amounts of six markers. Four markers (albumin, -2-microglobulin, cystatin C, and osteopontin) were undetectable in most AASK-N samples. Examination by SDS-PAGE followed by protein staining revealed protein profiles indicative of severe protein degradation in 34 of 37 AASK-N urine samples. Treatment of lupus nephritis urine samples with 0.5% acetic acid produced the same protein degradation profile as that of AASK-N urine. We conclude that the increased NAP in AASK-N is an artifact of acetic acid-mediated degradation of albumin. The AASK-N repository urine samples have been compromised by the acetic acid preservative.
Topics: Acetic Acid; Black or African American; Biological Specimen Banks; Cohort Studies; Humans; Preservatives, Pharmaceutical; Proteinuria; Proteolysis; Time Factors; Urine
PubMed: 28104821
DOI: 10.1681/ASN.2016080886 -
Applied and Environmental Microbiology Aug 2016The yeast Dekkera bruxellensis, associated with wine and beer production, has recently received attention, because its high ethanol and acid tolerance enables it to...
UNLABELLED
The yeast Dekkera bruxellensis, associated with wine and beer production, has recently received attention, because its high ethanol and acid tolerance enables it to compete with Saccharomyces cerevisiae in distilleries that produce fuel ethanol. We investigated how different cultivation conditions affect the acetic acid tolerance of D. bruxellensis We analyzed the ability of two strains (CBS 98 and CBS 4482) exhibiting different degrees of tolerance to grow in the presence of acetic acid under aerobic and oxygen-limited conditions. We found that the concomitant presence of acetic acid and oxygen had a negative effect on D. bruxellensis growth. In contrast, incubation under oxygen-limited conditions resulted in reproducible growth kinetics that exhibited a shorter adaptive phase and higher growth rates than those with cultivation under aerobic conditions. This positive effect was more pronounced in CBS 98, the more-sensitive strain. Cultivation of CBS 98 cells under oxygen-limited conditions improved their ability to restore their intracellular pH upon acetic acid exposure and to reduce the oxidative damage to intracellular macromolecules caused by the presence of acetic acid. This study reveals an important role of oxidative stress in acetic acid tolerance in D. bruxellensis, indicating that reduced oxygen availability can protect against the damage caused by the presence of acetic acid. This aspect is important for optimizing industrial processes performed in the presence of acetic acid.
IMPORTANCE
This study reveals an important role of oxidative stress in acetic acid tolerance in D. bruxellensis, indicating that reduced oxygen availability can have a protective role against the damage caused by the presence of acetic acid. This aspect is important for the optimization of industrial processes performed in the presence of acetic acid.
Topics: Acetic Acid; Dekkera; Hydrogen-Ion Concentration; Oxidative Stress; Oxygen
PubMed: 27235432
DOI: 10.1128/AEM.00515-16 -
BMJ Open Sep 2023Despite of recent advancement in the burns wound management, burn wound infection (BWI) is still one of the major cause of burns mortality. Patients who survive their...
INTRODUCTION
Despite of recent advancement in the burns wound management, burn wound infection (BWI) is still one of the major cause of burns mortality. Patients who survive their burns injury still suffers from BWI related complication like delayed wound healing and poor scarring. BWI has been treated by application of topical antimicrobial agents or systemic antibiotics. Due to the global risk of developing systemic antibiotics resistance, medical research focuses on identifying single topical agent which has effective antimicrobial activity, easily available and cost effective. One such agent is acetic acid (AA). AA has been used as a topical antibacterial agent for the treatment of burns wounds for many years and has shown to have activity against gram-negative organisms including . So far there has been no consensus on optimal concentration that has effective antimicrobial activity, frequency of application, duration of treatment and most importantly good patient's tolerability. A randomised control study is required to answer all these questions.
OBJECTIVE
To investigate the efficacy and tolerability of 0.5% and 2% of AA when applied to colonised burns wounds for 3 days after admittance to the Queen Elizabeth Hospital Birmingham.
METHODS AND ANALYSIS
This is a double-blinded, prospective, randomised, controlled, single-centre trial. Patients will be screened for eligibility in the inpatient area and those who are found to be eligible will be randomly assigned to one of two treatment groups: group 1: 0.5% AA (10 patients); group 2: 2% AA (10 patients); total number: 20 patients.
OUTCOME MEASURES
: Efficacy will be assessed by measuring the bacterial load from microbiology wound swabs for three consecutive days.: (1) The assessment of antimicrobial activity of AA and the minimum inhibitory concentrations. (2) Patient's tolerance by assessing Visual Analogue Scale pain score. (3) Time to 95% wound healing of treatment area. (4) Patient's perceived treatment allocation.
ETHICS AND DISSEMINATION
AceticA trial protocol was approved by the National Research Ethics Service (West Midlands-Edgbaston Research Ethics Committee; 17/WM/0407; IRAS 234132). This article refers to protocol version 5.0 dated 6 July 2020. The analysed results will be presented at national and international conferences related to management of burn patients. The generated articles based on the trial results will be submitted to peer review journals for publication.
TRIAL REGISTRATION NUMBER
ISRCTN11636684.
Topics: Humans; Acetic Acid; Pilot Projects; Prospective Studies; Burns; Anti-Bacterial Agents; Randomized Controlled Trials as Topic
PubMed: 37748846
DOI: 10.1136/bmjopen-2021-058006 -
Bioresource Technology Oct 2021The influence of the carbon source on the metabolism and growth of Clostridium aceticum was investigated, supplying either CO or fructose as sole carbon source. The acid...
The influence of the carbon source on the metabolism and growth of Clostridium aceticum was investigated, supplying either CO or fructose as sole carbon source. The acid and solvent production patterns were determined under either autotrophic or heterotrophic conditions, elucidating the effect of pH on the substrate's bioconversion pattern. The highest maximum specific growth rate was observed with CO, under the organism's optimal growth conditions, reaching 0.052 h and an acetic acid concentration of 18 g·L. The production of 4.4 g·L ethanol was also possible, after medium acidification, during CO bioconversion. Conversely, formic acid inhibition was observed during fructose fermentation under optimal growth conditions. In the latter experiments, it was not possible to stimulate solvent production when growing C. aceticum on fructose, despite applying the same medium acidification strategy as with CO, showing the selective effect of the carbon source (autotrophic vs heterotrophic) on the metabolic pattern and solventogenesis.
Topics: Acetic Acid; Bioreactors; Carbon Monoxide; Clostridium; Ethanol; Fermentation; Fructose
PubMed: 34320764
DOI: 10.1016/j.biortech.2021.125485